To reduce an Electro Magnetic Compatibility (EMC) common-mode interference, a current three-phase interleave converter with a Three-State Switching Cell (TSSC) is connected, using three safety capacitors (Y2 capacitors), to a wire and a Power Factor Correction (PFC) bus voltage to reduce common-mode interference.
A three-phase interleave converter with a three-state switching cell illustrated in FIG. 1 includes a filter circuit and a power factor correction circuit. Three safety capacitors (Y2 capacitors) are set in a conducting wire connecting the filter circuit to the power factor correction circuit, namely, Cx7, Cx8, and Cx9, where one end of the Cx7, one end of the Cx8, and one end of the Cx9 are connected together and the other ends are connected to the conducting wire. In addition, a star connection is also set in the conducting wire connecting the filter circuit to the power factor correction circuit. The Y2 capacitor is a type of safety capacitor specified by the International Electrotechnical Commission (IEC) 644 and is bridge-connected between the live wire or neutral wire of an electrical power, and the ground, where the basic insulation or supplementary insulation voltage ranges from 150 V to 250 V.
Because the rectifier modules are constantly miniaturized and achieving higher and higher efficiency, and the EMC filters are space-consuming, it is a good way to reduce the number of the EMC filters by increasing the power density of the module. In the circuit illustrated in FIG. 1, three Y2 capacitors are needed; the use of three safety capacitors (Y2 capacitors) is space-consuming and requires a lot of devices, which is unfavorable to improvement of the power density.